cancel2 2022
Canceled
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Scientists (Hambler and Henderson, 2022) find it is variation high latitude temperatures affecting sea ice extent changes that dominate as drivers of the CO2 (and methane) annual fluxes, not photosynthesis.
They affirm temperature (T) changes lead CO2 change rates by about 7-10 months, suggesting the causality direction is T→CO2, and not CO2→T.
Temperature also drives sea ice peak melt vs. accumulation rates. This cause-effect directionality can also be clearly seen in analyses of sea ice flux vs. annual CO2 rate changes.
“The phase relationship between temperature and carbon dioxide has been examined to help elucidate the possible direction of causality and the lags we find between timeseries are consistent with carbon dioxide being the response variable.”
“Carbon dioxide is very strongly correlated with sea ice dynamics, with the carbon dioxide rate at Mauna Loa lagging sea ice extent rate by 7 months. Methane is very strongly correlated with sea ice dynamics, with the global (and Mauna Loa) methane rate lagging sea ice extent rate by 5 months. Sea ice melt rate peaks in very tight synchrony with temperature in each Hemisphere.”
Abstract:
Background: The seasonal cycle of atmospheric carbon dioxide is usually ascribed to the seasonality of Northern Hemisphere vegetation, and the seasonal cycle of methane is usually ascribed to seasonal removal by the hydroxyl radical.
Objective: We test an alternative, that the cycles of these greenhouse gases might be linked to sea ice dynamics.
Method: Time-series analysis of carbon dioxide, methane, sea ice parameters, vegetation greenness (NDVI), and temperature. We consider a variable that lags another can not be causal of the leading variable.
Results: Carbon dioxide is very strongly correlated with sea ice dynamics, with the carbon dioxide rate at Mauna Loa lagging sea ice extent rate by 7 months. Methane is very strongly correlated with sea ice dynamics, with the global (and Mauna Loa) methane rate lagging sea ice extent rate by 5 months. Sea ice melt rate peaks in very tight synchrony with temperature in each Hemisphere. The very high synchrony of the two gases is most parsimoniously explained by a common causality acting in both Hemispheres.
Conclusion: Time lags between variables indicate primary drivers of the gas dynamics are due to solar action on the polar regions, not mid-latitudes as is conventionally believed. Our results are consistent with a proposed role of a high-latitude temperature-dependent abiotic variable such as sea ice in the annual cycles of carbon dioxide and methane. If sea ice does not drive the net flux of these gases, it is a highly precise proxy for whatever does. Potential mechanisms should be investigated urgently.
https://ora.ox.ac.uk/objects/uuid:e8c6fd34-d451-4456-8df8-038965585e02
Scientists (Hambler and Henderson, 2022) find it is variation high latitude temperatures affecting sea ice extent changes that dominate as drivers of the CO2 (and methane) annual fluxes, not photosynthesis.
They affirm temperature (T) changes lead CO2 change rates by about 7-10 months, suggesting the causality direction is T→CO2, and not CO2→T.
Temperature also drives sea ice peak melt vs. accumulation rates. This cause-effect directionality can also be clearly seen in analyses of sea ice flux vs. annual CO2 rate changes.
“The phase relationship between temperature and carbon dioxide has been examined to help elucidate the possible direction of causality and the lags we find between timeseries are consistent with carbon dioxide being the response variable.”
“Carbon dioxide is very strongly correlated with sea ice dynamics, with the carbon dioxide rate at Mauna Loa lagging sea ice extent rate by 7 months. Methane is very strongly correlated with sea ice dynamics, with the global (and Mauna Loa) methane rate lagging sea ice extent rate by 5 months. Sea ice melt rate peaks in very tight synchrony with temperature in each Hemisphere.”
Abstract:
Background: The seasonal cycle of atmospheric carbon dioxide is usually ascribed to the seasonality of Northern Hemisphere vegetation, and the seasonal cycle of methane is usually ascribed to seasonal removal by the hydroxyl radical.
Objective: We test an alternative, that the cycles of these greenhouse gases might be linked to sea ice dynamics.
Method: Time-series analysis of carbon dioxide, methane, sea ice parameters, vegetation greenness (NDVI), and temperature. We consider a variable that lags another can not be causal of the leading variable.
Results: Carbon dioxide is very strongly correlated with sea ice dynamics, with the carbon dioxide rate at Mauna Loa lagging sea ice extent rate by 7 months. Methane is very strongly correlated with sea ice dynamics, with the global (and Mauna Loa) methane rate lagging sea ice extent rate by 5 months. Sea ice melt rate peaks in very tight synchrony with temperature in each Hemisphere. The very high synchrony of the two gases is most parsimoniously explained by a common causality acting in both Hemispheres.
Conclusion: Time lags between variables indicate primary drivers of the gas dynamics are due to solar action on the polar regions, not mid-latitudes as is conventionally believed. Our results are consistent with a proposed role of a high-latitude temperature-dependent abiotic variable such as sea ice in the annual cycles of carbon dioxide and methane. If sea ice does not drive the net flux of these gases, it is a highly precise proxy for whatever does. Potential mechanisms should be investigated urgently.
https://ora.ox.ac.uk/objects/uuid:e8c6fd34-d451-4456-8df8-038965585e02
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